The slider breaks down about six inches and in by six inches to an opposite hand hitter. A left-handed pitcher’s slider breaks down and away from left-handed batters; down and in on right-handed batters. It appears to be a fastball but breaks at the last minute going about six to eight miles an hour slower than the fastball. It is one of the fastest pitches in baseball.

The pitcher is taking advantage of the Magnus Effect when throwing a fastball. The Magnus Effect is when a spinning sphere effects the air pressure around it. The side of the baseball spinning with the direction it is traveling moves against the air faster, creating more drag and pressure on the ball which causes the air to push on it. On the opposite side of the ball, air pressure is reduced which makes the ball travel easier in that direction when a spinning sphere effects the air pressure around.
Releasing the Slider ‘Out in Front maximizes it’s effectiveness. You are best positioned to finish the pitch and command the Slider to break how you wish. It’s going to break later and be drastically sharper. That what you want in this Dominant Pitch. The more consistently that you do this step, the more consistent your results will be. That’s what coaches and scouts want to see….and I know where you want to be as a pitcher….
I would recommend waiting until the player is 14 or 15 years old. If young players throw curveballs on a consistent basis at younger ages they can cause damage to their elbows and thus hinder the growth process. But it’s not only the fact that they are throwing curveballs at a young age, it’s the fact that they are throwing curveballs with improper mechanics that causes much of the damage. The key is to make sure they are throwing the curveball with proper pitching mechanics.
Armando Galarraga threw sliders 38.9% of the time in 2008, more than any other starting pitcher in the majors, and Ryan Dempster threw them 32.9% of the time, more than any other NL starting pitcher.[2] In 2008 CC Sabathia had the most effective slider, among major league starting pitchers.[3] Zack Greinke won the AL Cy Young award in 2009 in large part because of his slider, one of the better pitches in all of baseball.[4] In 2011, Clayton Kershaw won the Triple Crown by allowing only a .117 average against his slider.[5]
A well-timed curveball can be highly beneficial to pitchers, but a curveball is pretty useless if the batter knows it's coming so that he or she has time to adjust to the swing. For that reason, it's important that pitchers not only master the grip and motion of the curveball but also the secrecy of the grip itself, which is necessary for fooling the batter.
Let's begin. A pitcher will stand perpendicular to a straight line (like a foul line in the outfield grass or line on a gym floor). If the pitcher is on the pitching mound itself, he can use his spikes to drag out a straight line in the dirt 8-feet long and perpendicular to the rubber (i.e. directly in line with home plate). Then, he simply marks out the distance of his height and drags out a second line in the dirt--only this one is parallel to the pitcher's rubber. If the pitcher is not on a mound, he will simply place a second object like his hat on the ground. This will mark the distance he should be striding toward his target.
I hope you enjoyed and learned something from this compilation of the best baseball pitching drills. I suggest that if you haven’t already, check out my Pitching Mechanics page. It’s where I break down a lot of the proper mechanics in the pitching delivery. You should also check out my pitching program if you’re interested in throwing faster and more accurate.